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Predaceous Diving Beetle (Cybister fimbriolatus)


Detailing the physical features, habits, territorial reach and other identifying qualities of the Predaceous Diving Beetle.

 Updated: 10/15/2018; Authored By Staff Writer; Content ¬©www.InsectIdentification.org




The Predaceous Diving Beetle is a 'tiger' among the underwater larval insect world. Adults don't mind a little time on land either.



Predaceous Diving Beetle Videos



Predaceous Diving Beetles swimming and floating


Resting on underwater plants

Found in or near large ponds and lakes, the Predaceous Diving Beetle is hydrodynamic for a life mostly spent in water. It may look like it only has two front legs, but the other 4 legs are there and underneath it. The back legs are flat and used to propel it forward water. The front legs look like bent 'arms' with feathery hairs on all legs.

They feed on other aquatic insects and creatures, including small tadpoles. Males use their paddle-like feet to secure the female for mating. Both genders fly very well out of water and are attracted to lights at night. They are most active at night and can be seen moving from one water source to another (puddles, pools, ponds, flooded roads, etc.)

Larvae hatch underwater and look somewhat like long, tubular naiads (larval dragonflies) or centipedes (minus all but 6 legs). They have what appear to be pincers at the mouth which are likely used to catch and consume aquatic insects. They are ferocious predators and aggressive by nature.




Taxonomic Hierarchy
Kingdom: Animalia
  Phylum: Arthropoda
    Class: Insecta
      Order: Coleoptera
        Family: Dytiscidae
          Genus: Cybister
            Species: fimbriolatus
Identifying Information
Scientific Name: Cybister fimbriolatus
Category: Beetle
Size (Adult; Length): 26mm to 34mm (1.01in to 1.33in)
Colorwheel Graphic Colors: brown; yellow; black; green
Descriptors: arms, fins, water, smooth, feathery, flying, aggressive, long, tubular
Territorial Map
Alaska  
Hawaii  
Prince Edward Is.  
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Territorial Reach (A-to-Z)
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canadian National Flag Graphic
Alberta
British Columbia
Manitoba
New Brunswick
Newfoundland and Labrador
Nova Scotia
Ontario
Prince Edward Island
Quebec
Saskatchewan
Mexican National Flag Graphic
Mexico
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.




Beetle Anatomy
Graphic showing basic anatomy of a common North American Beetle insect
1
Antennae: Beetles have a pair of antennae on the head used as sensors.
2
Head: The head is home to the insect's eyes, antennae, and mandibles (jaws).
3
Thorax: Holds the three pairs of legs as well as vital internal organs.
4
Elytron: One of two wing cases on a Beetle that protects its wings (plural: elytra).
5
Wings: Appendages used for flying and kept under the elytra until needed.
6
Abdomen: Houses organs related to circulation, reproduction, and excretion.
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Legs: Beetles have three pairs of legs located at the thorax, numbering six legs in all.